Table 2: Line fluxes (available electronically at the CDS).

Ion	A 12	A 18	A 20	H3-75	IC 2003	IC 2165	J 320	J 900
H 4340	54.0	34.0	27.0	68.0	26.0	53.0	63.0	59.0
[O III] 4363	8.7	10.6	3.8	13.4	11.5	14.3	13.6	9.6
...	...	...	...	...	...	...	...	...